Machine for twisting flat metal bars.



No. 777,224. PATENTED DEC.13, 1904.

. G. SANDBLOM. MACHINE POR TWISTING FLAT METAL BARS.

APPLIGATIGN FILED AUG. 27, 1904.

N0 MODEL UNTTED STATES Patented December 13, 1904'.

PATENT OEEICE.

MACHINE FOR TWISTING FLAT METAL BARS.

SPECIFICATION forming part of Letters Patent N 0. 777,224, dated December 13, 1904. Application tiled August 27, 1904. Serial No. 222,392. (No model.)

To al?, whom t 11i/ty concern:

Be it known that I, GUsTAv SANDBLOM, a citizen of Sweden, residing at New York city, (Queens) county of Queens, and State of New York, have invented new and useful Improvements in Machines for Twisting Flat Metal Bars, of which the following' is a specification.

This invention relates to a machine for providing aflat metal bar with a bent section between its ends, bars of this character being used for bridle-irons and other purposes.

In the accompanying drawings, Figure 1 is a plan of the principal part of my improved machine; Fig. 2, alongitudinal section thereof on line 2 2, Fig. 1; Fig. 3, a front elevation; Fig. 4, a detail section on line 4, 4, Fig. 1; Fig. 5, a detail of one of the bearing-blocks and abutments, and Fig. 6 a perspective view of the twisted bar formed by the machine.

The object of the invention is to provide a flat bar A, Fig. 6, with a turned-down section A', which merges into the body of bar A by the twisted sections A2.

The letters L a represent a pair of parallel standards that support at one end a bed-plate 7), having a pair of slots t and a rib b2. To bed-plate 7) are adjustably secured in front of rib 62 a pair of bearing-blocks c, the distance between which may be regulated to conform Substantially to the distance between the outer corners A3 of the twisted sections A2. The connection between bearings c and bed-plate is effected by a groove and a key b3, which is arranged parallel te rib if. After the bearings c have been properly spaced they are locked in position by set-screws c entering' one of a number of tapped openings of plate 6 and by clamp-screws czpressing upon key t". The screws c2 also serve to connect a top plate d to each of the bearings c, such top plate overhanging the rear of the bearing, Figs. 2 and 4:. At its inner end each bearing c is recessed to accommodate a tapering abutment e, fulcrumed to the bearing at e. During the bending operation the abutments 0 are subjected to considerable strain, under which they will slightly turn inward and correspondingly relieve the inner corners of bearings c. Be tween the bearings c there projects through each of the slots an inclined gripper f, the

upper hook-shaped head f ofwhich is adapted to engage the upper edge of bar A vertically above the inner corner Al to be formed on the bar.

The grippers f are operated in the following manner: g is a power-shaft carrying crankdisk g, the wrist-pin g2 of which engages one end of pitman 7L. The other end of this pitman is connected at L to the lower arms of a pair of diverging' elbow-levers i, turning on spindlej, which is hung in bearings b5 of plate The upper arms of elbow-levers f2? are slotted to accommodate the Shanks of grippers j', Fig. 3, which are pivoted thereto at f2, Fig. 1. The rotation of the power-shaft g will thus by elbow-levers 2l cause a simultaneous `forward and downward motion, of grippers j. By this action the bar A is shaped in the manner desired, the turned-down section A being forced into an inclined surface-groove L of bed-plate This groove permits the section A/ to be bent downwardslightly in excess of ninety degrees, so that it will assume its cor rect position by the back spring' of the metal. rlhe grippers f are held in an upright position during the introduction of the worlcpiece by chains f3 and counterweights ft. The lower edge of bar A is engaged by a pair of hooks 1, that are arranged below grippers f and project through the slots of plate Each hook is fulcrumed to plate b at bl and is provided with a shank u, carrying an adjustable counterweight L2.

The operation is as follows: The bar A is placed on edge upon table L between rib t and bearings c, its bottom edge being engaged by hooks 71:. The grippers f are turned backward against action of counterweights j, and are thus brought into engagement with the upper edge of bar A. By now rotating shaft g the grippers are drawn downward and forward to bend the section A into a substantial horizontal position in the' manner desired. During the commencement of this action the hooks fr: will hold the lower edge of bar A against forward displacement and prevent the bar from becoming bulged.

What I claim is- 1. In a machine for twisting' flat metal bars, the combination of a bed-plate with a pair of IOO with a pair of bearings adjustably secured to the bed-plate, a top plate, a pair of movable abutments at the inner edges of the bearings, I5 and grippers and hooks intermediate the bearings, substantiaily as specified.

Signed by me at New York, (Manhattan) N. Y., this 25th day of August, 1904.

GUSTAV SANDBLOM.

Titness es:

WILLIAM SCHULZ, FRANK V. BRIESEN. 

